Refrigerating apparatus



R. E. GoULD l2,106,840

REFRIGERATING APPARATUS Filed Oct. 26, 1935 z8 j INVENTOR'.

RIN/Aka f. Gal/Lo H/S ATTORNEYS.

3g. 4 l y M, 4

Patented Feb. l, 1938 o fr GIERG APPRFTUS Richard E. Gould, yton, @bien assigner to General Motors Coge Dayton, @hid a coration of elaware application @ctober 2d, i935, Serial No. 4631i@ 5 Gi. (Ci. 22d-9) This invention relates to reirigerating appara= tus and more particularly to the construction of cabinets for such apparatus.

An object of the invention is to provide an improved refrigerator cabinet construction.

Another object of the invention isI to provide a refrigerator cabinet that will be light in weight and constructedof elcient ,insulating material which will not absorb moisture.

Another object of the invention is to provide a refrigerator cabinet with rigid metallic interior and exterior wall surfaces which are maintained in spaced apart relation by a relatively thick insulating structure formed of cellular rubber ina- 5 terial having an impervious crust or outer surface vulcanized Ato the metallic interior and exterior walls of the cabinet.

A further object of the invention is to utilize the crust or impervious oute.V surface of the in- 2o sulating structure as a means for covering and concealing the spaced apart edges of thev inner and outer metallic wall surfaces of the cabinet as a means for providing a finished impervious insulating breaker strip between the edges of the 25 metal walls about the cabinet access opening.

In'carrying out the foregoing objects, it is a still further object of the invention to bond the insulating material to the inner and outer metallic wall surfaces of the cabinet to cause the outer 3c metallic wall to form the sole support for the inner wall and the insulating material.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accom--A 35 panying drawing wherein a preferred form of the` present invention is clearly shown.

In. the drawing: Fig. 1 is a, iront elevational view of a refrigerator cabinet constructed according to the presfic ent invention;

Fig. 2 is a horizontal sectional view through the refrigerator cabinet taken on the line 2 2 of Fig. 1;

Fig. 3 is an enlarged fragmentary horizontal 45 sectional view through a corner of the cabinet at the access opening thereof and showing a door closing the opening;

Fig. 4 is a sectional view showing a portion of 5 a mold abutting the bounding surface of the door opening of the cabinet during the process of heating the structure to cause formation of a. crust on the insulating material about the cabinet access opening; and

55 Fig. 5 is a sectional view showing portions of molds positioned along certain wall surfaces of a door for the refrigerator cabinet. A

ferring to the drawing, for the purpose of illustrating my invention, I have shown in Fig. l thereof a refrigerator cabinet, generally repre- 5 sented by the reference character it, constructed in accordance with the teaching of the present invention. Cabinet it includes a metal lining member i i forming a plurality of horizontal and vertical walls of a food storage chamber l2 withlo in the cabinet. Lining member il is surrounded by an insulating material it which will be more fully described hereinafter. A metal shell it is disposed over and surrounds the insulating marenal as and chamber ir. sneu it extends teyond the insulating material i3 and chamber or compartment i2 at the bottom of cabinet it to form walls of a compartment adapted to house or enclose a reirigerating machine to be associated with the cabinet. This extension of shell id is also adapted to have legs i5 secured thereto and in this manner, it is obvious that the shell it serves as the sole supporting member or structure for the compartment l2 and insulation it. Cabinet i@ is provided with an opening il which adords access to compartment i2 and which opening is adapted to be closed by a door generally represented by the reference character it and constructed in a manner to be hereinafter described. A cooling element i9 of any suitable 30 construction is adapted to be mounted within compartment i2 for cooling and causing circulation of air therein. The food chamber i2 is divided into a plurality of superimposed compartments by shelves 2i secured therein in any suit- 35 able and well known manner. It will be noted that the shell id is of a one-piece tubular form and extends continuously across the front side of the cabinet, having the access opening il provided therein, and continuously across adjacent sides and the back of the cabinet. A flat sheet metal plate 22 has a downwardly turned ange welded or otherwise secured to the tubular shell it to close the open upper end thereof. Another flat sheet metal plate (not shown) but similar to plate 22 is located within the shell it below the insulating material i3 at the bottoml of the compartment i2 and has its peripheral edges welded or otherwise securedto the inner surfaces of shell it. The two iiat sheet metal plates are preferably secured to shell I4 in such a manner as to hermetically seal the insulation within the shell.

Having described the general construction of the cabinet, I will now proceed to describe the .55

steps in the making of same and particularly the method of providing the layer of insulating material I3. The fiat metal plate (not shown) but which extends parallel with the bottom wall of liner I I and in spaced relation thereto, to provide a space for the insulation I3 along the bottom wall of liner IIl is welded or otherwise secured in shell I4 at a predetermined point intermediate the open ends of the shell. 'I'he liner member II is then placed within shell I4 and is held in spaced relation to the walls of the shell by a suitable fixture 26 oftsubstantially rectangular form (see Fig. 4). It will be noted (see Fig. 4) that the fixture 26 has outwardly extending portions 21 which engage an outwardly bent flanged portion 28 provided on liner II and an inwardly bent flanged portion 28 provided in the front wall of shell I4 about the access opening I1. It is through engaging portions of fixture 26 with the liner Il and shell I4 which holds the liner in spaced relation to shell I4. The edge surface of the rectangular hollow fixture 26 intermediate the raised portions 21 thereon is in the form of a groove having tapered side walls emerging into the raised portions 21. This groove is for a pulDOse to be hereinafter more fully described. After the lower sheet metal plate has been welded or otherwise secured to shell I4, a predetermined amount of a dough or paste is placed between the liner II and shell I4. 'I'he top sheet metal plate 22 is then welded or otherwise secured or sealed to walls of the shell I4 to close the space intermediate the liner II andshell I4 about the compartment I2. The paste or dough may be of any suitable substance for carrying out the objects of the invention and may, for example, consist of rubber having a nitrogen gas mixed ory commingled therewith or the dough -may comprise a mixture of rubber and dry ammonia and/or sodium carbonate. It is to be understood that the amount of dough or paste mixture placed between liner I I and shell I4 must be predetermined through experimentation and that ,the chamber containing same must be vented during the application of heat to the dough to form the cellular insulation I3 so as to prevent bulging or deformation of the walls of liner I I and shell I4. These walls must also be reinforced against deformation, as for example, by being placed in suitable forms.

Having assembled or placed the elements above described together in the manner explained, the dough mixture is ready to be heated to cause expansion thereof between the Walls of liner II and shell I4. Heat may be applied to the dough mixture in any suitable or well known manner such, for example, as by placing the entire structure including the fixture 26 and other suitable reinforcing forms in an oven or by directing steam through the fixture 26 and other molds or fixtures placed into abutting relation with walls of the liner II and shell I4. Heating of the structure causes the mass of dough or paste mixture to expand in the chamber between liner II and shell I4. As before stated, any suitable or desirable means for venting and permitting air trapped in the insulating chamber to escape may be employed. Expansion of the dough mixture is similar to the expansion of dough in the ordinary process of making bread wherein the ammonium kor sodium carbonate upon being heat- "ed forms carbon dioxide and expands the mass into a cellular structure. The rubber constituent of the dough mixture, upon contacting the heated walls of liner II and shell I4, becomes bonded thereto and also forms a hard impervious crust adjacent these walls. Heat being less intense toward the center of the chamber to be filled with the insulation I3, causes the dough mixture to form a substantially cellular structure intermediate the hard bounding crust. The mixture which flows into the groove intermediate the raisedportions 21 of fixture or mold 26 forms a hard impervious crust adjacent the groove which embeds and becomes bonded to the edges of the flanged portions 28 and 29 of liner 'II and shell I4 respectively. The crust adjacent the groove in fixture or mold 26 also forms an insulating breaker strip for the cabinet which extends between the edges of the flanges 28 and 29. The structure is permitted to cool and the fixture or mold 26 and other molds employed in heating the structure may then be readily removed therefrom. By virtue of the fact that the tapered Wall along the inner raised portion 21 of fixture or mold 26 is parallel with walls`of liner II, the mold 26 may be moved horizontally away from the cabinet structure. Any suitable or desirable inserts employed to secure door hinges or other hardware to cabinet II) may, of course, be welded or otherwise secured to the inner surface of shell I4 prior to the assembling and heating operations. The entire structure may, during the heating operation thereof, be rotated in various directions to insure uniform flow and expansion of the dough mixture to all portions of the chamber to be occupied by the expanded insulation.

The door I8 of cabinet I0 may be formed in substantially the same manner as the insulated walls of the cabinet. For example, a metal pan 3I, which will serve as the inner wall surface of door I8, may be placed in a substantially rectangular hollow fixture or mold 32 (see Fig. 5) and a predetermined amount of the doughmixture is then placed upon the pan 3|. mold 33 may then be fitted into the upwardly directed walls 34 of mold 32 to form a substantially closed chamber in which the dough mixture upon the pan 3| may be heated and caused to expand. After the door insulation has been formed and permitted to cool, the fixtures or molds 32 and 33 are removed therefrom and other elements of the door construction are assembled or secured to the door insulation. For example, a wooden frame 36 may be attached to the door insulation by screws 31 secured to a metal insert 38 bonded to the door insulation during formation thereof. A gasket 39 secured to frame 36 engages the front surface of shell I4 to seal the door opening 'I1 when the door opening is closed. It will be noted that the mold or fixture 32 has a groove formed therein which provides, when the dough mixture is expanded in the door, a' raised or paneled edge surface on the door insulation which serves as an impervious exposed peripheral outer portion of the door I8 to match or conform with the periphery of the cabinet door opening I1. The metal walls of cabinet I and the exposed hard crust of insulation I3`at the door opening I1 thereof may be uniformly coated with any desirable paint or other coating.

The expanded rubber mixture which forms the insulation I3 is of better insulating properties than that generally used in refrigerator cabinets and is also much lighter in weight and does not absorb moisture.I The formation of the layer of hard crust in the insulating material about the A fixture or` outer surfaces thereof which encloses the integral cellular structure in forming an impervious insulating breaker strip about the walls of the door opening il eliminates the necessity of 'attaching other iinished strips of wood or other material to these Walls and thus eliminates the unsightly appearance of attaching means therefor. Thus, rusting and deterioration of attaching means ordinarily employed for securing breaker strips to refrigerator cabinets about the door openings thereof are eliminated by my improved cabinet construction. It will also be apparent that the chamber containing the expanded rubber insulation is substantially sealed from ingress oi' moisture and that the shell id extends continuously around the four vertical sides of the cabinet and forms the sole support for the insulation i3 and food compartment |12.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims winch follow.

What is claimed is as follows:

i. An insulated wall' structure comprising, spaced apart sheet metal members having an expanded rubber insulation therebetween, each of said sheet metal members having an aperture therein registering with one another to provide an opening in said structure, and said insulation having a hard impervious crust bonded to said members and extending from the edge `of the aperture in one of said members to the edge ci the aperture in the other of said members to form the Walls of said opening and to seal the space between the metal members.

2. An insulated wall structure comprising, spaced apart sheet metal members having an expanded rubber insulation therebetween, each of said sheet metal members having an aperture therein registering with one another to provide an opening in said structure, and said insulation having a hard impervious crust bonded to said members and extending from the edge of the aperture in one or" said members to the edge of the aperture in the other of saidmembers to form the walls of said opening and to seal the space between the metal members, and a door having a seal engaging one of said metal members for closing said opening.

3. An insulated wall structure comprising, spaced apart sheet metal members having an expanded rubber insulation therebetween, each of said sheet metal members having an aperture therein registering with one another to provide an opening in said structure, and said insulation having a hard impervious crust embedding the edges of the spaced apart sheet metal members about the opening in the wall structure, said impervious crust being bonded to the edges of said members and extending therebetween to form walls of said opening in the structure and to seal the space between the metal members.

4. A refrigerator cabinet comprising a boxlike structure including an inner metal liner forming walls of a compartment to be cooled within said cabinet and having an access opening, a sheet metal member spaced from said liner walls and having an opening registering with 'the opening in said liner, insulating material between the walls of said liner and said sheet metal member for maintaining same in spaced apart relation, said sheet metal member forming a support ior said liner and said insulating ma terial and forming as wellouter finish walls of said cabinet, said insulating material including an expanded rubber insulation having a hard impervious crust bonded to said liner and to said outer sheet metal member, and said impervious insulating crust extending between the edge of the opening in said liner and the edge of the opening in said outer sheet metal member and forming the walls oi said opening.

5. A Wall structure comprising, sheet metal members spaced apart and forming a chamber therebetween, insulating material within said chamber, an edge of one of said members being spaced from an edge of the other of said members to break the metal-to-metal contact therebetween and to define an opening for said chamber, and said insulating material comprising expanded rubber having a hard crust bonded to said edges of said sheet metal'members and extending therebetween to form a wall for said opening for sealing the space between said members.

RICHARD E. GOULD. 

